The existing printer includes a printing mechanism and a paper storage fixedly connected with a frame, where a paper roll for printing is placed in the paper storage, and printing paper (i.e. a printing medium) may lead out from the paper roll to be printed by the printing mechanism and outputted to the outside of the printer. Due to the fact that a user needs to use different types of paper rolls depending on a specific case in some scenarios, there is a need for easy replacement of the paper roll in the printer, to improve the work efficiency.
International application Publication No. WO2007111235 provides a printer with a detachable paper storage. As shown in FIG. 1A, a printer 1′ includes a body 2′, an upper cover 3′ and a paper storage 4′ for accommodating printing paper, where the upper cover 3′ is pivoted with side walls 14a and 15a of the body 2′ and may be rotatably opened or closed relative to the body 2′. A printing head 21′ is arranged in the body 2′, and a roller 22′ is arranged on the upper cover 3′, so that when the upper cover 3′ is closed relative to the body 2′, the printing head 21′ tangentially matches with the roller 22′.
A first space portion 34′ is formed between the side walls 14a and 15a of the body 2′, and a second space portion 35′ is formed between side arms 32′ and 33′ of the upper cover 3′. The paper storage 4′ is mounted in a space formed by the first space portion 34′ and the second space portion 35′. The paper storage 4′ includes a first part 4a and a second part 4b, where a first slot 45′ and a second slot 46′ of the second part 4b match with a first inserting pin 39′ and a second inserting pin (not shown) on the body in a plugging manner, and a first inserting tab 40′ and a second inserting tab 41′ of the second part 4b match with the side walls 14a and 15a of the body 2′ in a plugging manner; while clamping detents 51′ and 52′ of the first part 4a match with the two side arms of the upper cover 3′ in a clamping manner, so that when the upper cover 3′ is rotatably opened relative to the body 2′, the first part 4a is accordingly opened. After the paper storage 4′ is installed in the printer, as shown in FIG. 1B, a leading end of the printing paper is pulled out from the paper roll and then the upper cover 3′ is closed, in this case, the printing paper is pressed between the roller 22′ and the printing hear 21′ and hence printing can be started. The printer can selectively adopt paper storages having different structural sizes to utilize paper rolls with different outer diameters.
However, the existing printer is defective in that: replacement by a paper roll with a different outer diameter requires for replacement by a paper storage having a different structural size, which requires for installing the first part and the second part of the paper storage respectively, and each time the paper roll is being installed, the upper cover is opened so as to pass the printing paper between the roller and the printing head, thus the operations of replacing the paper roll for such printer are complicated, causing inconvenience in use.